Per design/IMPLEMENTATION-ORDER.md 1.1 and decision D-007: the domain
model takes the quest vocabulary pre-release. SCHEMA_V1 now creates
quest_definitions/quest_instances directly; DAO classes, records and
error messages follow (QuestDefinitionsDao, QuestInstancesDao). The
migration runner gains migration 2, an async-callable step that detects
surviving task_* tables on dev machines and ALTER TABLE RENAMES them
inside the migration transaction, with FK clauses rewritten by SQLite.
Migration 1's content rewrite is legal because nothing was ever
shipped; dev databases stamped version 1 ride migration 2 up to 2.
Joshua King